Toothbrush

ABSTRACT

A toothbrush that can more effectively clean an interdental gap, a gap between a tooth and gums, a dental groove, and a surface of the tooth and the gums. 
     In the toothbrush, a bristle implanting section is formed so that a bristle implanting surface is in an elliptical shape of which the major axis direction corresponds to the longitudinal direction of a handle when viewed from the tip part side of bristle bundles. The brush section includes a plurality of center bristle bundles arranged along the major axis direction at the center of the ellipse in the minor axis direction and a plurality of side bristle bundles arranged on both sides of the plurality of center bristle bundles in the minor axis direction. At least, the center bristle bundles are formed to be gradually inclined upwardly from both sides to the center of the ellipse in the major axis direction.

TECHNICAL FIELD

The present invention relates to a toothbrush for removing stains such as dental plaque attached to a tooth by using a brush section that is a handle end in which bristles are implanted.

BACKGROUND ART

Generally, a toothbrush is composed of a handle formed longitudinally so as to be grasped tightly and a brush section that is an end of the handle in which bristles are implanted. By grasping and moving the handle, a tip of the brush section formed on the end of the handle hits a tooth to remove stains such as dental plaque attached to the tooth.

In recent years, there has been a problem on how to efficiently remove stains not only on a surface of a tooth, but also between teeth (namely, in an interdental gap), on a boundary between a tooth and gums and in a dental groove. A type of toothbrush is available to address this problem. Namely, the configuration of the brush section thereof is devised so that the brush section efficiently enters between the teeth and into other parts. For example, the toothbrush disclosed in patent document 1 is configured so that the brush section is formed in a chevron shape in whole when viewed from the lateral side of the toothbrush. In other words, the brush section is cut so as to be gradually inclined upwardly toward the center of the brush section. Thus, compared to the case that the surface of the brush section is cut in a planar shape, a top part of the chevron-shaped brush section is easier to enter into an interdental gap and a gap between a tooth and gums (so-called “periodontal pocket”) and a dental groove.

However, even if the tip of the brush section formed in the chevron shape in whole such as the toothbrush disclosed in patent document 1, this type of toothbrush might not be able to effectively remove dental plaque on the surface of the tooth, in the interdental groove and in the gap between the tooth and the gums.

RELATED ART DOCUMENTS Patent Documents

-   [Patent Document 1] Japanese Patent Application Publication No.     2012-075725

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

The present invention was made in view of an above-mentioned point, and the purpose is to provide a toothbrush that can more effectively clean an interdental gap, a gap between a tooth and gums, a dental groove and a surface of the tooth and the gums by brushing for a short time and with light force.

Means of Solving the Problems

The present invention to solve the above-mentioned problem has in one embodiment, a longitudinal handle (11), a bristle implanting section (12) having a bristle implanting surface (12 a) formed at a tip of the handle (11) and a brush section (20) configured to include a plurality of bristle bundles (22, 23 a, 23 b) composed of a large number of bristles implanted on the bristle implanting surface (12 a). In a toothbrush (1) for cleaning teeth by using the brush section (20), the bristle implanting section (12) is formed in a shape of an ellipse having the major axis direction (P) and the minor axis direction (Q) when viewing the bristle implanting surface (12 a) from a side of tip parts (22T, 23 aT, 23 bT) of the bristle bundles (22, 23 a, 23 b). The brush section (20) has the bristle bundles (22, 23 a, 23 b) including a plurality of center bristle bundles (22) arranged along the major axis direction (P) at the center of the ellipse in the minor axis direction (Q) and side bristle bundles (23 a, 23 b) arranged on both outer sides of the plurality of center bristle bundles (22) in the minor axis direction (Q). At least, the center bristle bundles (22) are characteristically formed in a chevron shape so as to be gradually inclined upwardly from both sides toward the center of the ellipse in the major axis direction (P). In addition, in this case, the bristle implanting section (12) may be formed in an elliptical shape of which the major axis direction (P) corresponds to the longitudinal direction of the handle (11).

In another embodiment, the present invention has the longitudinal handle (11), the bristle implanting section (12) having the bristle implanting surface (12 a) formed at the tip of the handle (11) and the brush section (20) configured to include the plurality of bristle bundles (21, 22, 23 a, 23 b) composed of a large number of bristles implanted on the bristle implanting surface (12 a). In a toothbrush (1-2) for cleaning teeth by using the brush section (20), the bristle implanting section (12) is formed in the shape of the ellipse having the major axis direction (P) and the minor axis direction (Q) when viewing the bristle implanting surface (12 a) from the side of the tip parts (21T, 22T, 23 aT, 23 bT) of the bristle bundles (21, 22, 23 a, 23 b). The brush section (20) has the bristle bundles (21, 22, 23 a, 23 b) including a top bristle bundle (21) that is positioned at the center of the ellipse in the major axis direction (P) and in the minor axis direction (Q) and the highest of a plurality of the bristle bundles (21, 22, 23 a, 23 b), a plurality of center bristle bundles (22) arranged on both sides of the top bristle bundle (21) along the major axis direction (P), and a plurality of side bristle bundles (23 a, 23 b) arranged on both sides of the plurality of the center bristle bundles (22) in the minor axis direction (Q). At least, the plurality of the center bristle bundles (22) are characteristically formed in the chevron shape so as to be gradually inclined upwardly from both ends toward the top bristle bundle (21) in the major axis direction (P). A tip part (21T) of the top bristle bundle (21) is characteristically at a position that is higher than an intersecting point (X) of ridgelines (R) formed by connecting tip parts (22T) of the plurality of the center bristle bundles (22). In addition, in this case also, the bristle implanting section (12) may be formed in an elliptical shape of which the major axis direction (P) corresponds to the longitudinal direction of the handle (11).

In the toothbrush of the above-described configuration in accordance with the present invention, as the bristle implanting surface of the bristle implanting section is formed in the shape of the ellipse having the major and minor axis directions when viewed from the tip part side of the bristle bundles, the bristles of the brush section (namely, bristle bundles) are arranged in a curved line along the outer periphery of the ellipse. Accordingly, compared to a bristle implanting section formed into a rectangle shape, the bristle implanting section of the present invention can prevent an edge part of the bristle implanting section (namely, the tip of the handle) and the bristle bundles on the outer peripheral side of the brush section from interfering parts in the mouth (such as teeth, gums and an inner surface of a cheek) needlessly. Therefore, a move of the brush section only with light force enables smooth and efficient brushing. Moreover, as the bristles (bristle bundles) of the brush section are arranged in the curved shape along the outer periphery of the ellipse, a stroke of the toothbrush enables the tip of the bristles (bristle bundles) to effectively touch (namely, slide to) an upper surface and a side surface of the tooth having a complex uneven shape and an interdental gap. Consequently, stains can be removed more efficiently from the dental groove and the interdental gap. Furthermore, compared to a bristle implanting section formed in a circular shape (perfect circular shape), the bristle implanting section of the present invention can secure a longer distance (linear dimension) of the brush section along the longitudinal direction of the handle, namely, the stroke direction of the toothbrush. Accordingly, a proportionally larger area contacting with the tooth can be secured in the brush section. This enables more effective removal of dental stains. The toothbrush of the present invention having the bristle implanting section formed in the above-described elliptical shape can thus provide the above-described multiple effects in combination and remove stains in the dental groove and the interdental gap efficiently.

In addition, in the toothbrush in accordance with the present invention, at least a part of the bristle bundles of the brush section are formed in the chevron shape so as to be gradually inclined upwardly toward the center of the above-described ellipse in the major axis direction. This enables the tip of the center bristle bundle at the highest position of the brush section to enter deeply into the gap between the tooth and the gums and the interdental gap without being interfered by the neighboring bristle bundles, and stains at a deeper position to be scraped securely as the plurality of the side bristle bundles support the center bristle bundles that have entered in the deeper position.

Moreover, as the bristle implanting section is formed in the elliptical shape and the side bristle bundles are arranged on both sides of the center bristle bundles (in the minor axis direction), the plurality of the side bristle bundles uniformly contact with the surface of the tooth and gums around the part that the center bristle bundle enters into. Furthermore, as far as the side bristle bundles are also formed in the chevron shape so as to be gradually inclined upwardly toward the center of the side bristle bundles, when lower ones of the bristle bundles on the further outer peripheral side abut to a tooth, higher ones of the side bundles on the center side can abut to a further inner tooth without interfering between the side bristle bundles. This enables the side bristle bundles to clean the surfaces of the teeth and the gums around the gaps and the grooves effectively.

Moreover, in the toothbrush (1, 1-2) of the above-described configuration in accordance with the present invention, the side bristle bundles (23) may include first side bristle bundles (23 a) arranged on a side closer to the center bristle bundle (22) and second side bristle bundles (23 b) arranged on a side farther from the center bristle bundle (22) in the minor axis direction (Q). Furthermore, in this case, it is desirable that the first side bristle bundles (23 a) are higher than the neighboring second side bristle bundles (23 b). According to this configuration, the shape of the brush section is formed so that the bristles (bristle bundles) gradually lower toward both sides of the ellipse from the center of the bristle implanting section in the minor axis direction. Therefore, as the tip of the first side bristle bundle (23 a) at the higher position can enter into a deeper position in the gap (MG) between the tooth (T) and the gums (M) and the dental groove (TU) without being interfered by the neighboring bristle bundles, the stains at the deeper position can be scraped off.

Moreover, in the toothbrush including the above-described top bristle bundle (21) in accordance with the present invention, this top bristle bundle (21) should be configured to be higher than the center bristle bundles (22) and the side bristle bundles (23) that are arranged around the top bristle bundle (21). Thus, while the center bristle bundles (22) and the side bristle bundles (23), which are inclined in the chevron shape (pyramid shape), are cleaning the interdental gap and the surface of tooth (T) adjacent to the gap between the tooth and the gums, the tip part (21T) of the top bristle bundle (21) enters deeply into the groove (TU) on the surface of the tooth (T), the interdental gap (TG) and the gap (MG) between the tooth (T) and the gums (M). Accordingly, the dental groove, the dental gap and the gap between the tooth and the gums can be cleaned more effectively by brushing for a short time and with light force.

Moreover, in the toothbrush in accordance with the present invention, the center bristle bundles (22) excluding the top bristle bundle (21) and the side bristle bundles (23) are formed to be inclined in the chevron shape (pyramid shape). Thus, compared to a toothbrush with a normal (conventional) planar tip, the center bristle bundles (22) and the side bristle bundles (23) can cleanse the surface of the tooth, the interdental gap and the dental groove more effectively. Further, if the tip part (21T) of the top bristle bundle (21) is at a position that is higher than the intersecting point (X) of the ridgelines (R) formed by connecting the tip parts (22T) of the plurality of the center bristle bundles (22), stains deeper in the dental groove, the interdental gap and the gap between the teeth and the gums can be scraped by the tip part (21T) of the top bristle bundle (21). Therefore, these effects enable the toothbrush of the present invention to effectively remove stains in the whole oral cavity including the interdental gap and the gap between the tooth and the gums by brushing for a short time and with light force. It should be noted that the bracketed reference numerals are examples of the elements of the embodiment described later.

Effects of the Invention

The toothbrush in accordance with the present invention can provide the above-described effects as the bristle implanting section is formed so that the bristle implanting surface thereof is in the elliptical shape having the major and minor axis directions when viewed from the tip side of the bristle bundles. Therefore, the toothbrush can more effectively clean the interdental gap, the gap between the tooth and the gums and the dental groove, and the surface of the tooth and the gums by brushing for a short time and with light force.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating a whole toothbrush in accordance with a first embodiment of the present invention;

FIG. 2 are enlarged views of a brush section of the toothbrush of the first embodiment, of which FIG. 2A is a plan view, FIG. 2B is a side view and FIG. 2C is a front view;

FIG. 3 is a view illustrating a state of cleaning an interdental gap when viewing teeth from the above;

FIG. 4 is a view illustrating a state of cleaning a gap between a tooth and gums when viewing the tooth and the gums from sideways; and

FIG. 5 are enlarged views of a brush section of a toothbrush in accordance with a second embodiment, of which FIG. 5A is a plan view, FIG. 5B is a side view, and FIG. 5C is a front view.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First Embodiment

FIG. 1 is a view illustrating a whole toothbrush in accordance with one embodiment of the present invention. The toothbrush has a main body including a longitudinal handle 11 (11A, 11B) and a bristle implanting section 12 having a bristle implanting surface 12 a formed at a tip of the handle 11, and a brush section 20 configured to include bristle bundles (namely, center bristle bundles 22 and side bristle bundles 23 a, 23 b), which will be described later, composed of a number of bristles implanted on the bristle implanting surface 12 a.

The handle 11 has a gripper 11A that a user grasps, a neck section 11B with resilience due to a configuration thereof narrower in width than the gripper 11A. According to this configuration, the user cleans a tooth T (illustrated in FIGS. 3 and 4 ) by holding the gripper 11A and then moving the brush section 20 at the tip of the handle 11. It should be noted that the handle 11 of the toothbrush 1 is made of relatively hard synthetic resinous materials such as polypropylene, and the bristles of the bristle bundles of the brush section 20 (namely, the center bristle bundles 22, first side bristle bundles 23 a and second side bristle bundles 23 b, which will be described below) are made of relatively soft synthetic resinous materials such as nylon.

The bristle implanting section 12 of the toothbrush 1 is formed so that the bristle implanting surface 12 a (upper surface) thereof is in an elliptical shape of which the major axis direction P corresponds to the longitudinal direction of the handle 11 when viewed from a tip part (upper end) 22T, 23 aT, 23 bT side (namely, from the front side of the paper, on which FIG. 1 is printed) of the bristle bundles 22, 23 a, 23 b. Moreover, the elliptical shape of the bristle implanting section 12 and the brush section 20 of the toothbrush 1 should be preferably, for example, approximately 2 cm in length in the major axis direction so as to easily enter an oral cavity and then turn in a small radius.

The brush section 20 of the toothbrush 1 will be described in detail. FIG. 2 are enlarged views of the brush section 20, of which FIG. 2A is a plan view, FIG. 2B is a side view and FIG. 2C is a front view. As shown in FIGS. 2 , the bristles forming the brush section 20 are classified into the center bristle bundles 22, the side bristle bundles 23 a, 23 b (namely, the first bristle bundles 23 a and the second bristle bundles 23 b) according to where in the bristle implanting section 12 (specifically, where on the bristle implanting surface 12 a) the bristles are implanted. In other words, the brush section 20 is composed of a plurality of the center bristle bundles 22 arranged (in sequence) along the major axis direction P of the bristle implanting section 12 in a center area AC in the minor axis direction Q and a plurality of side bristle bundles 23 a, 23 b arranged in areas AS1, AS2 adjacent to the center bristle bundles 22 in the minor axis direction Q. Next, configurations of the center bristle bundles 22 and the side bristle bundles 23 a, 23 b will be described in detail.

As shown in FIG. 2A, the center bristle bundles 22 are composed of a plurality of the bristle bundles and arranged (in line) in the area AC along the major axis direction P. In this embodiment, eight disposed bundles of the center bristle bundles 22 are illustrated as one example. The plurality of the center bristle bundles 22 are formed in a chevron shape (pyramid shape) so as to be gradually inclined upwardly toward the center in the major axis direction P. Specifically, as shown in FIG. 2B, the plurality of the center bristle bundles 22 are formed to be inclined so that four bundles thereof on the handle 11 side are gradually elevated linearly toward an end part of the handle 11 and the other four bundles on the end part side are gradually lowered linearly toward the end part of the handle 11. In addition, as shown in FIGS. 2B and 2C, the center bristle bundles 22 are configured to be higher than the neighboring side bristle bundles 23 a, 23 b.

As shown in FIG. 2A, the plurality of the side bristle bundles 23 a, 23 b are arranged adjacent to the center bristle bundles 22 in the areas AS1, AS2 on both outer sides of the center bristle bundles 22. Furthermore, the plurality of the side bristle bundles 23 a, 23 b include the first side bristle bundles 23 a arranged in the area AS1 on a side closer to the center bristle bundles 22 (namely, on an inner side of the bristle implanting surface 12 a) in the minor axis direction Q and the second side bristle bundles 23 b arranged in the area AS2 on a side farther from the center bristle bundles 22 (namely, an outer side of the bristle implanting surface 12 a) in the minor axis direction Q.

In this embodiment, as one example, seven bundles of the first side bristle bundles 23 a are arranged each on both sides of the center bristle bundles 22, and four bundles of the second side bristle bundles 23 b are arranged each on outer sides of the first side bristle bundles 23 a. Specifically, as shown in FIG. 2B, the first side bristle bundles 23 a are formed to be inclined so that the center one in the major axis direction P is highest while the other three ones on the handle 11 side are gradually elevated linearly toward the end part of the handle 11 and the other three ones on the end part side of the handle 11 are gradually lowered linearly toward to the end part of the handle 11. Further, the second side bristle bundles 23 b are formed to be inclined so that two ones on the handle 11 side are gradually elevated linearly toward the end part of the handle 11 and the other two ones on the end part side of the handle 11 are gradually lowered linearly toward to the end part of the handle 11.

As shown in FIG. 2B, an inclination angle θ1 of a line connecting tips 22T of the center bristle bundles 22 inclined in the chevron shape, an inclination angle θ2 of a line connecting tips 23 aT of the first side bristle bundles 23 a and an inclination angle θ3 of tips 23 bT of the second side bristle bundles 23 b are all the same. In addition, the center bristle bundles 22 are configured to be harder in material than the side bristle bundles 23 a, 23 b. In this connection, the center bristle bundles 22 may be larger in quantity than the side bristle bundles 23 a, 23 b. This can maintain high hardness of the brush section 20. It should be noted that while the center bristle bundles 22 are arranged in line along the major axis direction P in this embodiment, but not necessarily limited thereto. The center bristle bundles 22 may be arranged in a plurality of rows. Further, the number of the side bristle bundles 23 a, 23 b (the first and second side bristle bundles 23 a, 23 b) are also not limited to number in this embodiment.

FIGS. 3 and 4 are views illustrating use states of the toothbrush 1 cleaning a gap TG between a tooth T and a tooth T (namely, interdental gap) and a gap MG between a tooth T and gums M, of which FIG. 3 is a view when viewing a plurality of the teeth T from the above and FIG. 4 is a view when viewing the tooth T and the gums M from sideways. As shown in FIGS. 3 and 4 , the toothbrush 1 of this embodiment is used by applying the brush section 20 to a surface TS of the tooth T and between the tooth T and the gums and then moving the brush section 20 little by little, thereby cleaning the tooth T and the gap MG between the tooth T and the gums M.

At this time, as the center bristle bundles 22 and the side bristle bundles 23 a, 23 b are disposed on the elliptical bristle implanting surface 12 a, strokes of the toothbrush 1 enable the tips 22T, 23 aT, 23 bT of the bundles (namely, bristle bundles 22, 23 a, 23 b) of the brush section 20 to effectively touch (slide to) an upper surface and a side surface of the tooth having a complex uneven shape and a gap TG between the teeth T. This enables more effective clearance of stains in a groove TU of the tooth T and the interdental gap TG. In addition, as the center bristle bundles 22 and the side bristle bundles 23 a, 23 b are inclined in the chevron shape (pyramid shape), the tip of the chevron shape easily enters into the groove TU of the tooth T, the interdental gap TG and the gap MG between the tooth T and the gums M. This can scrape stains at a deep position in the groove TU of the tooth T, the interdental gap TG and the gap MG between the tooth T and the gums M. Moreover, as the bristle implanting surface 12 a is in the elliptical shape and the center bristle bundles 22 and the side bristle bundles 23 a, 23 b are in the chevron shape, not only the center bristle bundles 22 and the side bristle bundles 23 a, 23 b positioned at the tip of the chevron shape, but also the center bristle bundles 22 and the side bristle bundles 23 a, 23 b adjacent to this tip can easily enter into the groove TU of the tooth T, the interdental gap TG and the gap MG between the tooth T and the gums M. Therefore, these synergistic effects can effectively scrape stains in the overall oral cavity including the interdental gap TG and the gap MG between the tooth T and the gums M by brushing for a short time and with light force.

In addition, as the bristle implanting surface 12 a of the toothbrush 1 are in the elliptical shape and the center bristle bundles 22 are configured to be higher than the side bristle bundles 23 a, 23 b on both sides, a tip part 21T of the center bristle bundles 22 and a tip part 22 aT, 22 bT of the side bristle bundles 23 a, 23 b inclined in the chevron shape (pyramid shape) enter deep into the groove TU of the tooth T, the interdental gap TG and the gap MG between the tooth T and the gums M. This can scrape the stains that have entered into the groove TU of the tooth, the interdental gap TG and the gap between the tooth M and the gums M by brushing for a short time and with light force.

Further, as described above, the inclination angle θ1 of the center bristle bundles 22 inclined in the chevron shape and the inclination angles θ2, θ3 of the side bristle bundles 23 a, 23 b similarly inclined in the chevron shape are all the same. Thus, when the tip part 21T of the center bristle bundles 22 enters deeply into the gap MG between the tooth T and the gums M and the dental groove TU, the side bristle bundles 23 a, 23 b adjacent to the center bristle bundles 22 in the minor axis direction Q enter into and thus abut to, at the same inclination angle with the center bristle bundles 22, the tooth T and the gums M adjacent to where the tip part 21T of the center bristle bundles 22 enters deeply. In this manner, the center bristle bundles 22 and the side bristle bundles 23 a, 23 b effectively clean the gap MG between the tooth T and the gums M, the dental groove TU and the neighboring parts of the tooth T and the gums M. Thus, the toothbrush of the present invention can scrape the stains in the overall oral cavity including the interdental gap and the gap between the tooth and the gums by brushing for a short time and with light force.

Further, as shown in FIG. 3 , the toothbrush 1 of this embodiment, the linear dimension L1 of the bristle implanting section 12 in the major axis direction P is set in a width dimension L2 of two teeth T. Accordingly, as the teeth T can be easily cleaned two by two, the interdental gap TG and the gap MG between the tooth T and the gums M can be easily brushed one by one, which enables effective cleaning for a shorter time.

As described above, the toothbrush 1 of this embodiment has the longitudinal handle 11 and the bristle implanting section 12 having the bristle implanting surface 12 a formed at the end part of the handle 11 and the brush section 20 configured to include the plurality of the bristle bundles configured by a number of bristle bundles 22, 23 a, 23 b implanted on the bristle implanting surface 12 a. And, in the toothbrush 1 that cleans the teeth by using the brush section 20, the bristle implanting section 12 is formed so that the bristle implanting surface 12 a thereof is in the elliptical shape of which the major axis direction P corresponds to the longitudinal direction of the handle 11 when viewed from the tip part 22T, 23 aT, 23 bT side of the bristle bundles 22, 23 a, 23 b. Further, the brush section 20 includes as the bristle bundles 22, 23 a, 23 b, the plurality of the center bristle bundles 22 arranged along the major axis direction P in the center area AC of the ellipse in the minor axis direction Q and the plurality of the side bristle bundles 23 a, 23 b arranged in the areas AS1, AS2 on both outer sides of the plurality of the center bristle bundles 22. And, the center bristle bundles 22 and the side bristle bundles 23 a, 23 b are formed so as to be gradually inclined upwardly from both sides toward the center of the ellipse in the major axis direction P.

In the toothbrush of this embodiment, as the bristle implanting surface 12 a is formed in the shape of the ellipse of which the major axis direction P corresponds to the longitudinal direction of the handle 11 when viewed from the tip part 22T, 23 aT, 23 bT side of the bristle bundles 22, 23 a, 23 b, the bristles (bristle bundles) of the brush section 20 are arranged in the shape of a curved line along the outer periphery 12 b of the ellipse. Accordingly, compared to a bristle implanting section formed into a rectangle shape, when brushing the teeth by using the brush section 20, the toothbrush of the present invention can prevent an edge part of the bristle implanting section 12 (namely, the end part of the handle 11) and the bristle bundles on the outer peripheral side of the brush section 20 from interfering parts in the mouth (such as teeth, gums and an inner surface of a cheek) needlessly. Therefore, a move of the brush section 20 only with light force enables smooth and efficient brushing.

Moreover, as the bristles (bristle bundles) of the brush section 20 are arranged in the curved shape along the outer periphery of the ellipse, the strokes of the toothbrush 1 enable the tip of the bristles (bristle bundles) to effectively touch (namely, slide to) the upper surface and the side surface of the tooth having a complex uneven shape and interdental gap. Consequently, the stains can be removed more efficiently from the dental groove and the interdental gap.

Furthermore, compared to an outer periphery of a bristle implanting section formed in a circular shape (perfect circular shape), the bristle implanting section 12 of the present invention can secure a longer distance (linear dimension) of the brush section 20 along the longitudinal direction of the handle 11, namely, the stroke direction of the toothbrush 1. Consequently, a larger contact area of the brush section can be secured by that amount. This enables more effective removal of dental stains. Thus, in the toothbrush 1 of this embodiment, the outer periphery 12 b of the bristle implanting section 12 formed into the above-described elliptical shape can provide the above-described multiple effects in combination.

In addition, as the tips (upper ends) of the center bristle bundles 22 and the side bristle bundles 23 a, 23 b are configured to be inclined in the chevron shape (pyramid shape), the tip of the center bristle bundles 22, which is the highest of the plurality of the center bristle bundles 22 and the plurality of the side bristle bundles 23 a, 23 b, can enter, without being interfered by the neighboring bristle bundles, into a deep position of the gap MG between the tooth T and the gums M and the dental groove TU. Thus, the stains in the deep position can be scraped off. Furthermore, as the plurality of the center bristle bundles 22 are formed in the chevron shape, the second highest center bristle bundle 22 adjacent to the highest center bristle bundles 22 also easily enters into the interdental gap MG and the dental groove TU following the highest center bristle bundle 22. The same applies to the plurality of the side bristle bundles 23 a, 23 b similarly formed in the chevron shape.

Further, as the center bristle bundles 22 are configured to be higher than the side bristle bundles 23 a, 23 b on both sides, when the center bristle bundles 22 enter into the deepest part of the gap MG between the tooth T and the gums M and the dental groove TU, the side bristle bundles 23 a, 23 b lower than the center bristle bundles 22 easily enter into the tooth T and the gums M adjacent to the deepest part following the center bristle bundles 22.

Moreover, as the inclination angle θ1 of the center bristle bundles 22 inclined in the chevron shape and the inclination angles θ2, θ3 of the side bristle bundles 23 a, 23 b similarly inclined in the chevron shape are all the same, when the center bristle bundles 22 enters deeply into a deep part of the gap MG between the tooth T and the gums M and the dental groove TU, the side bristle bundles 23 a, 23 b adjacent to the center bristle bundles 22 in the minor axis direction Q enter into and thus abut to, at the same inclination angle with the center bristle bundles 22, the tooth T and the gums M adjacent to where the center bristle bundles 22 enters deeply. In this manner, as the center bristle bundles 22 and the side bristle bundles 23 a, 23 b effectively clean the gap MG between the tooth and the gums M and the dental groove TU, and the neighboring part of the tooth T and the gums M by brushing for a short time and with light force, whereby the toothbrush 1 of the present invention can scrape the stains in the overall oral cavity including the interdental gap and the gap between the tooth and the gums.

In addition, in the toothbrush 1 of the above-described configuration, the center bristle bundles 22 may be configured to be harder in material than the side bristle bundles 23 a, 23 b. In this manner, if the bristle bundles 21, 22 that are elevated gradually towards the center of bristle implanting section 12 are hardened gradually towards the center of the bristle implanting section 12, the brush section 20 can maintain high hardness. Consequently, cleaning performance of the center bristle bundles 22 when entering deeply into the interdental gap TG, the gap MG between the tooth T and the gums M and the dental groove TU can be maintained at a high level.

Furthermore, in the toothbrush 1 of the above-described configuration, the center bristle bundles 22 may have a larger amount of bristles than the side bristle bundles 23 a, 23 b. A larger amount of the bristles of the center bristle bundles 22 can improve the hardness of the center bristle bundles 22 that are longer than the side bristle bundles 23 a, 23 b. Thus, cleaning performance of the center bristle bundles 22 when entering deeply into the interdental gap TG, the gap MG between the tooth and the gums M and the dental groove TU can be maintained at a high level.

Second Embodiment

Next, a second embodiment of the present invention will be described below. In the description of the second embodiment and the corresponding figures, like reference characters refer to components corresponding or equivalent to those of the first embodiment, and a detailed description thereof is dispensed with. FIGS. 5 are enlarged views of a brush section 20 of a toothbrush 1-2 of the second embodiment, of which FIG. 5A is a plan view, FIG. 5B is a front vies and FIG. 5C is a side view.

A bristle implanting section 12 (bristle implanting surface 12 a) of the toothbrush 1-2 of this embodiment is formed in the elliptical shape similar to the bristle implanting section 12 of the toothbrush 1 of the first embodiment. And, as shown in FIGS. 5 , the bristles forming the brush section 20 of the toothbrush 1-2 are classified into a top bristle bundle 21, center bristle bundles 22 and side bristle bundles 23 a, 23 b (namely, first bristle bundles 23 a and second bristle bundles 23 b) according to where in the bristle implanting section 12 (bristle implanting surface 12 a) the bristles are implanted. In other words, the brush section 20 is composed of the top bristle bundle 21 at the center of the bristle implanting section 12, a plurality of the center bristle bundles 22 arranged in line with the top bristle bundle in the major axis direction P and a plurality of the side bristle bundles 23 a, 23 b arranged adjacent to the center bristle bundles 22 in the minor axis direction Q. Each of these bristle bundles 21, 22, 23 will be described in detail below.

First, a configuration of the top bristle bundle 21 will be described. The top bristle bundle 21 is positioned at the center of the bristle implanting section 12 (bristle implanting surface 12 a). Here, the center of bristle implanting section 12 refers to the center of the elliptical bristle implanting section 12 in the major axis direction P and in the center of the minor axis direction Q in the plan view of the bristle implanting section 12 (bristle implanting surface 12 a) as shown in FIG. 5A. The top bristle bundle 21 is formed so that a tip part 21T thereof is the highest of tip parts of the bristle bundles 21, 22, 23. Specifically, the tip part 21T of the top bristle bundle 21 is at a higher position than an intersecting point X of ridgelines R formed by connecting the tip parts 22T of the center bristle bundles 22 (See FIG. 5B). Therefore, the tip part 21T of the top bristle bundle 21 is projected from the center bristle bundles 22 and the side bristle bundles 23 a, 23 b.

Further, as shown in FIGS. 5B and 5C, the tip part 21T of the top bristle bundle 21 is formed in a sharp conical shape. In addition, the top bristle bundle 21 should be preferably configured to be harder than the center bristle bundles 22 and the side bristle bundles 23 a, 23 b to achieve high hardness. Specifically, materials of the top bristle bundle 21 should be hardened more than materials of the center bristle bundles 22 and the side bristle bundles 23 a, 23 b, and the brush bristle constituting the top bristle bundle 21 should be thickened more than the center bristle bundles 22 and the side bristle bundles 23 a, 23 b. Moreover, the amount of the top bristle bundle 21 (namely, thickness of the bristle bundle) should be preferably larger than the amount of the center bristle bundles 22 or the side bristle bundles 23 a, 23 b to achieve higher hardness of the bristle bundle.

Next, the center bristle bundles 22 and the side bristle bundles 23 a, 23 b will be described. As shown in FIG. 5A, the center bristle bundles 22 are composed of a plurality of the bristle bundles and arranged in a center area AC of the bristle implanting section 12 in the minor axis direction Q. In addition, the side bristle bundles 23 a, 23 b are composed of a plurality of the bristle bundles and arranged in side areas AS1, AS2 on both sides of the center area AC of the bristle implanting section 12 in the minor axis direction Q. Furthermore, the side bristle bundles 23 a, 23 b include first side bristle bundles 23 a arranged in the area AS1 on a side closer to the center bristle bundles 22 (namely, on the inner side) in the minor axis direction Q, and second side bristle bundles 23 b arranged in the area AS2 on a side farther from the center bristle bundles 22 (namely, on the outer side) in the minor axis direction Q.

The center bristle bundles 22 are arranged in line on both sides in the major axis direction P so as to sandwich the top bristle bundle 21. In addition, the first side bristle bundles 23 a are arranged in line in the major axis direction P in the first side area AS1 outside of the center area AC, and the second side bristle bundles 23 b are arranged in line in the major axis direction P in the second side area AS2 outside of the first side area AS1. It should be noted that in this embodiment, each of the center bristle bundles 22, the first side bristle bundles 23 a and the second side bristle bundles 23 b is arranged in line along the major axis direction P, but not limited thereto. In other words, each of the center bristle bundles 22, the first side bristle bundles 23 a and the second side bristle bundles 23 b may be arranged in two lines or more.

As shown in FIG. 5B, the center bristle bundles 22, the first side bristle bundles 23 a and the second side bristle bundles 23 b are formed in the chevron shape (pyramid shape) to be gradually inclined upwardly toward the center (in the major axis direction P) of the bristle implanting section 12 when viewed from the side of the brush section 20. Furthermore, as shown in FIG. 5C, the center bristle bundles 22 are formed to be higher than the first side bristle bundles 23 a adjacent in the minor axis direction Q of the bristle implanting section 12, and the first side bristle bundles 23 a are formed to be higher than the second side bristle bundles 23 b similarly adjacent in the minor axis direction Q.

In the toothbrush 1-2 of this embodiment, as the top bristle bundle 21 is configured to be higher than the neighboring center bristle bundles 22 and the side bristle bundles 23 a, 23 b, the tip part 21T of the top bristle bundle 21 enters deeply into the groove of the tooth T, the interdental gap TG and the gap MG between the tooth T and the gums M while the center bristle bundles 22 and the side bristle bundles 23 a, 23 b, of which the tip parts are inclined in the chevron shape (pyramid shape), are cleaning the surface TS of the tooth T adjacent to the interdental gap TG and the gap MG between the tooth T and the gums M. This can scrape the stains that have entered into the groove TU of the tooth T, the interdental gap TG and the gap MG between the tooth T and the gums M for a short time and with light force.

While one embodiment of the present invention has been described above, the invention is not limited to the above-mentioned embodiment, but various modifications are possible within the scope of the technical idea as defined in the claims, the specification, and the drawings. For example, in the toothbrush 1 (1-2) of the above-described embodiment, the bristle implanting section 12 is formed in the elliptical shape, of which the major axis direction P corresponds to the longitudinal direction of the handle 11, but not limited thereto. In other words, the elliptical shape of the bristle implanting section of the toothbrush of the present invention may be formed so that the major axis direction thereof is different from the longitudinal direction of the handle. 

1. A toothbrush comprising: a longitudinal handle; a bristle implanting section having a bristle implanting surface formed at an end of the handle; and a brush section including a plurality of bristle bundles composed of a large number of bristles implanted on the bristle implanting surface, the toothbrush cleaning a tooth with the brush section, wherein the bristle implanting section is formed so that the bristle implanting surface is in an elliptical shape having a major axis direction and a minor axis direction when viewed from a tip part side of the bristle bundles, wherein the brush section includes as the bristle bundles, a plurality of center bristle bundles arranged along the major axis direction at a center of the ellipse in the minor axis direction and a plurality of side bristle bundles arranged on both sides of the plurality of the center bristle bundles in the minor axis direction, and wherein at least the center bristle bundles are formed in a chevron shape so as to be gradually inclined upwardly from both sides toward the center of the ellipse in the major axis direction.
 2. A toothbrush comprising: a longitudinal handle; a bristle implanting section having a bristle implanting surface formed at an end of the handle; and a brush section including a plurality of bristle bundles composed of a large number of bristles implanted on the bristle implanting surface, wherein in the toothbrush cleaning a tooth by using the brush section, the bristle implanting section is formed so that the bristle implanting surface is in an elliptical shape having a major axis direction and a minor axis direction when viewed from a tip part side of the bristle bundles, wherein the brush section includes as the bristle bundles, a top bristle bundle positioned at a center of the ellipse in the major axis direction and in the minor axis direction, the top bristle bundle being the highest of the plurality of the bristle bundles, a plurality of center bristle bundles arranged on both sides of the top bristle bundle along the major axis direction and a plurality of side bristle bundles arranged on both sides of the center bristle bundles in the minor axis direction, wherein at least the plurality of the center bristle bundles are formed in a chevron shape so as to be gradually inclined upwardly from both ends in the major axis direction toward the top bristle bundle, and wherein the tip part of the top bristle bundle is at a higher position than an intersecting point of ridgelines formed by connecting tip parts of the center bristle bundles.
 3. A toothbrush according to claim 2, wherein a number of bristles constituting the top bristle bundle is larger than a number of one of the center bristle bundles and the side bristle bundles.
 4. A toothbrush according to claim 1, wherein the bristle implanting section is in an elliptical shape of which the major axis direction corresponds to the longitudinal direction of the handle.
 5. A toothbrush according to claim 1, wherein the side bristle bundles include in the minor axis direction, first center bundles arranged on a side closer to the center bristle bundles and second bristle bundles arranged on a side farther from the center bristle bundles.
 6. A toothbrush according to claim 5, wherein the first side bristle bundles are higher than the neighboring second side bristle bundles.
 7. A toothbrush according to claim 1, wherein the center bristle bundles are higher than the neighboring side bristle bundles. 